A Novel Ultra-wideband Electromagnetic Wave-absorbing Metastructure Inspired by Bionic Gyroid Structures.

Traditional honeycomb-like structural electromagnetic (EM) wave-absorbing materials have been widely used in various equipment as multifunctional materials. However, current EM wave-absorbing materials are limited by narrow absorption bandwidths and incident angles because of anisotropic structural morphology. The work presented here proposes a novel EM wave-absorbing metastructure with an isotropic morphology inspired by the gyroid microstructures seen in Parides sesostris butterfly wings. A matching redesign methodology between the material and subwavelength scale properties of the gyroid microstructure is proposed, inspired by the interaction mechanism between microstructure and material properties on the EM wave-absorption performance of the prepared metastructure. Bioinspired metastructure is fabricated by additive manufacturing (AM) and subsequent coating through dipping processes, filled with dielectric lossy materials. Based on simulations and experiments, the metastructure designed in this work exhibits an ultra-wide absorption bandwidth covering the frequency range of 2-40 GHz with a fractional bandwidth of 180% at normal incidence. Moreover, the metastructure has a stable frequency response when the incident angle is 60° under the transverse electric (TE) and transverse magnetic (TM) polarization. Finally, the synergistic mechanism between microstructure and material is elucidated, which provides a new paradigm for the design of novel ultra-broadband EM absorbing materials. This article is protected by copyright. All rights reserved.